676 . MR. C. TATE REGAN ON THE 



Synopsis of the Genera. 



I. Scales cycloid or very finely denticulate. 



A. Pharyngeal apophysis formed by parasphenoid only. 

 Teeth in narrow or moderately broad bands, outer bicuspid, 



inner tricuspid 1. Tilapia. 



Teeth very small, in very broad bands 2. Corematodus. 



Teeth in a few series, slender, with expanded crowns, 



the outer obliquely truncated 3. SemUilapia. 



B. Pharyngeal apophysis formed bj' parasphenoid in middle and prootics at 



sides. 



Teeth moderate, outer mostly bicuspid, inner tricuspid 4. Otopharpix. 



Teeth very stout, unicuspid 5. Chilotilapia. 



II. Scales usually distinctly denticulate. Pharyngeal apophysis formed by para- 



sphenoid in middle and basioccipital at sides. 



A. Bones of head with small muciferous canals with small pores. 



1. Prsniaxillaries without anterior beak-like expansion. 



a. Edge of membrane of spinous dorsal produced into lappets, 

 a. Teeth conical, or outer bicuspid and inner tricuspid. 

 Teeth of outer series in upper jaw first decreasing and then 

 increasing in size antero-posteriorly ; band of teeth in 



lower jaw crescentic 6. Astatotilapia. 



Upper jaw with a rather broad band of small cuspidate 

 teeth anteriorly and a series of enlarged conical teeth 

 on each side ; lower jaw with a band of teeth with 

 incurved lateral edges, from ■which a single series runs 



back on each side 7. Tsewlotropliews. 



Teeth conical ; loAver jaw with 4 anterior canines 8. Cijnotilapia. 



Teeth conical ; no canines ; 7 to 9 series of scales on cheek . 9. Serranochromis^ 

 Outer teeth decreasing in size posteriorly; no distinct 

 canines ; bands of teeth continuous ; 2 to 6 series of 



scales on cheek 10. HaplocJiromis: 



Teeth very small and slender, forming narrow bands which 



are interrupted at the symphyses 11. LetJirinops. 



p. Outer teeth verj^ broad, compressed, with or without a pair of small 



lateral cusps 12. Docimodus. 



h. Edge of membrane of spinous dorsal running evenly between the tips of 

 the spines 13. Cyrtoeara. 



2. PrKmaxillaries with an anterior beak-like expansion. 



14. RliampTiocliromis. 



B. Frontals, nasals, orbitals, pranpercular and mandibulary bones deeply 



excavated, with, large openings 15. A ulonocara. 



1. Tilapia A. Smith, 1840 

 (type T. sparmanni A. Smith). 



Teeth small or moderate, in several sei'ies, the outer bicuspid, 

 the inner tricuspid (sometimes conical in large fish). Scales 

 cycloid or feebly denticulate. Pharyngeal apophysis formed by 

 parasphenoid only. 



Africa ; numerous species. 



The four species found in Nyassa may be distinguished as 

 follows ■.^- 



I. Three anal spines. 



A. Caudal scaled only at the base. 



Maxillary extending to below eye 1. mossambica. 



Maxillar3' not extending to below eye ; 2. melanopleura. 



B. Caudal covered with small scales 3. sqitamipinnis. 



II. Four anal spines : ... 4. sJiirana. 



